Mail 
Findley Lucas
How to split a large MBOX file
Google Takeout hands you one giant MBOX file, often several gigabytes. Here is how to split it into import-ready pieces with Thunderbird and ImportExportTools NG, step by step, without your mail ever leaving your computer.
How to use categories and custom categories
Aster Mail can sort your inbox into tabs like Primary, Promotions, Social, and Updates, and let you build custom categories that match mail by sender domain or subject keyword. Here is how to set it all up, and why the sorting never leaves your device.
How to set up two-factor authentication
Add a second layer of protection to your Aster account with authenticator app based two-factor authentication. Here is how to turn it on, scan the QR code, and keep your backup codes safe.
What ghost aliases are and how they work
Ghost aliases are temporary email addresses that deliver straight into your inbox without exposing your real address, then remove themselves automatically. Here is how they work under the hood.
How to import your email into Aster
Moving to Aster does not mean leaving your old mail behind. Here is how to bring it over, either with a one-click connection to Gmail or Outlook, or by importing a file yourself.
How to export your data
Aster lets you download a full copy of your account whenever you like. Here is what an export contains, how to run one, and how to keep the file safe.
How our CDN relay works
Aster's Connection setting has two options: Direct and CDN Relay. Here's exactly what the relay changes about your network path, what it does not do, and why it never hides your IP from us.
How to tell a real Aster email from a fake one
The blue badge on Aster's own emails has a specific meaning. Here is exactly what it checks, why it cannot be faked, and how to tell a genuine message from us apart from a phishing attempt.
How our decentralized storage works
There's a switch in your settings that takes your files out of our database entirely. Here's exactly what it does, where your encrypted files end up, and what we can still see, with nothing dressed up.
Introducing Aster Vanguard Lockdown Mode
Lockdown Mode is a one-tap security state in Aster Vanguard that blocks all external content, hides notification previews, and stops screenshots on the Aster apps, with no accidental way to turn it off. Built for journalists, activists, and high-risk accounts.
Password-protected, quantum-safe messages to anyone
How Aster lets you send encrypted, password-protected messages to Gmail and Outlook users using ML-KEM-768 post-quantum encryption, with no keys required on their end.
Our code audit, and the fixes
Our code audit, and the fixes
Can I change my username?
Your Aster username is permanent because it is also your email address and encryption identity. Here is why it cannot be renamed, and the two reliable ways to end up with the name you want.
Why Aster won't become the next Skiff
Skiff's shutdown left users scrambling. Here's why Aster is built differently: no investors steering us toward a sale, AGPL code that outlives the company, and standard OpenPGP keys you can take anywhere.
Hi, we're Aster. Here's what we care about.
Aster's mission and the five values we won't trade away: privacy as a right, security that's easy, full open source, no lock-in, and answering to users, not investors. With receipts.
What happens when your subscription ends
A plain explanation of what changes the moment your paid plan ends. What we keep, what gets paused, what you can still do, and how to get back where you were without losing anything.
What does "end-to-end encrypted" really mean
An exact list of what Aster Mail encrypts on your device, what our servers can still see, and an honest explanation of why each piece of metadata exists.
How Aster encrypts your email
A complete, honest look at how Aster encrypts your email — from key derivation and post-quantum protection to the metadata we store in plaintext and why.
Why our storage costs so little
10 GB free and low upgrade prices. Here's the full picture on how we keep storage affordable - the infrastructure decisions, the trade-offs we made, and why this model holds up long-term.
Is Aster Safe If It's Based in the US?
Aster is a US company with servers in Germany. Here's exactly what US law can and can't compel us to hand over - and why client-side encryption means even a valid court order can't get them your emails.
Sustainability Commitments
No venture capital. No advertising. No exit strategy. How Aster is funded, how we're structured, and why we're committed to staying independent. We wrote this to be held against us.
Aster is getting a new look!
We refreshed the Aster Mail logo and visual identity. Here's what changed, what we kept, and the thinking behind every decision in the updated design.
How our warrant canary and transparency report work
What our warrant canary actually proves, what shows up in our transparency report, and how to independently verify both. A practical guide to the legal protections behind Aster Mail.
Introducing Aster Mail: the world's most private email
Aster Mail is here. Free, open source, end-to-end encrypted with post-quantum protection and zero-access architecture. Everything private email should have been from the start.